The Multi-Protocol Label Switching (MPLS) technology, as a key technology in the Next Generation Network, has been playing a more and more important role in Internet Protocol (IP) networks. At the beginning, the MPLS technology was put forward to increase the forwarding speed of routers; however, it has now been widely applied in the fields of traffic engineering, Virtual Private Network (VPN) and Quality of Service (QoS) because of its own advantages and is becoming an important standard in large-scale Internet Protocol (IP) networks.
By further improvement, the MPLS technology has evolved into General MPLS (GMPLS) technology gradually. At present, the GMPLS technology is applicable to packet switched networks, such as Ethernet network, etc. In packet switched networks where the GMPLS technology is applied, data packets are forwarded through label switching technology, therefore the packet switched networks are generally called label switched networks. While the GMPLS technology has become a key technology for a multi-service bearer of IP networks, it has become a pressing issue to manage Label Switched Paths (LSPs) for identifying forwarding routes of data packets in label switched networks.
Particularly, in a label switched network maintained by multiple network operators or a large-scale label switched network maintained by one network operator, an LSP usually goes through multiple domains managed by different manager units. Such an LSP needs not only end-to-end supervision, but also respective supervision of different segments of the LSP in different supervision domains to determine indexes of performance and reliability of all segments of the label switched network.
According to the existing protocols, existing label switched networks can provide an end-to-end Operation and Maintenance (OAM) mechanism for LSPs. However, with respect to an LSP going through multiple supervision domains maintained by multiple network operators or manager units, the OAM mechanism mentioned above may not provide internal performance maintenance and supervision for each supervision domain respectively, but only end-to-end overall performance maintenance and supervision. As a result, it is impossible to determine the QoS of each supervision domain, thus impossible to determine responsibility when an LSP offers poor performance.